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Apr 29

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Seminar: Mantis-inspired advanced structural biomaterials

Shahrouz Amini, a final year Ph.D. student in Prof. Ali Miserez’s group, will be giving a seminar talk on their seminal work that was just recently featured in the Straits Times a few days ago about Mantis-inspired advanced structural biomaterials. His topic is on Chemo-Mechanical Gradients and Anisotropy in the Stomatopods Dactyl Club. Read More…

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Shahrouz Amini 1, Ali Miserez 1,2
1 Materials Science and Engineering, Nanyang Technological University, Singapore
2 School of Biological Sciences, Nanyang Technological University, Singapore
Abstract – Biography

Venue: Meeting Room 2-2
Date and time: Tue, Apr 29, 2-4pm

Actual Article: Straits Times News Feature B6

Abstract:

Biological composites have evolved fascinating strategies to exhibit superior structural properties. These hierarchical biomaterials utilize natural design principles to optimize static properties and fulfill their multi-functional requirements. Among this, biomineralized hard tissues are designed to achieve remarkable mechanical performance. The spearer mantis shrimp is a predatory animal known for mortal strikes using its predatory biotool. This highly mineralized and damage-tolerant biological tool is used to destroy prey’s armour by exerting repetitive high-energy punches. It is reported that the claw is capable of exerting hundreds Newtons of forces, which is enough to destroy a crustacean’s hard shell. Some of these hard shells are mimicked as damage-tolerant models.

Optical and electron microscopic studies revealed three distinct layers within the dactyl club. While the inner layers consist of successive fibrous layers, the outer layer is highly crystalline with crystal size decreasing 10-fold towards the free surface. Polarized microscopy showed birefringence properties of the most outer layer that can be correlated to preferred crystallite orientation. Raman spectroscopy studies of cross sectional samples highlighted a dominant amorphous calcium phases within the inner layers with increased gradient-like crystallinity of fluorapatite of the outer layer.

Nanoindentation studies on cross sectional samples showed a step-wise decrease in elastic modulus and hardness from the outer layer towards the inner most layers. Furthermore, 3D nanoindentation revealed statistically significant differences between elastic modulus in X, Y and Z planes that is correlated to preferred crystalline orientation toward the impact surface. Confocal Raman imaging and energy dispersive X-ray spectroscopy (EDS) mapping visualized the elemental and mineral phase distribution in the impact region correlating the site specific crystallo-chemistry and the relationships with the local mechanical properties.

Permanent link to this article: http://xml.sutd.edu.sg/announcement/seminar-mantis-inspired-advanced-structural-biomaterials